The incident allegedly occurred in an apartment in Carrick-on-Shannon, Co Leitrim. As part of a detailed probe, gardai have interviewed all five men at the centre of the woman’s claims along with some of their other friends and her pals.

Two were subsequently arrested and a file on the case is expected to be sent to prosecutors shortly.

A number of searches have also been carried out by gardai involved in the probe which has led to the seizure of a number of cannabis plants at a ‘small grow house’ which was connected to one of the suspects.

A senior source said: “This has been a difficult and complex investigation but a file is almost ready for the DPP.

“The woman in the case was certainly left in a traumatic state.”

It has emerged that the alleged victim – a woman in her twenties from Northern Ireland – had been at a hen party with several friends in Carrick-on-Shannon.

Sources say that the woman got separated from her friends and met a young man in a fast food restaurant in the town.

She travelled back to a nearby apartment that the young man and others who had been on a stag party with him had rented for the weekend.

It was in this property that the woman alleged she was gang-raped by up to five men in an ordeal that she reported lasted for a number of hours.

After she made the complaint to officers at Carrick-on-Shannon garda station, a major investigation began and gardai were able to identify the suspects using CCTV as well as through detailed local enquiries.

This led to gardai to interview a number of suspects and carry out searches, one of which led to the discovery of a small cannabis grow-house.

“They all deny that any rape happened,” said a source.

“This is a very difficult investigation from a number of different viewpoints.

“Everyone that is alleged to have been involved in the incident had a lot of alcohol on board.

“In the case of the woman, the question has to be whether she was in a fit state of mind to consent to sexual intercourse.

“If she was not, then this is rape. But with so much alcohol on board, the reliability of everyone’s account needs to be closely examined.